DPP9
Description
The DPP9 (dipeptidyl peptidase 9) is a protein-coding gene located on chromosome 19.
Dipeptidyl peptidase 9 is an enzyme that in humans is encoded by the DPP9 gene. This gene encodes a protein that is a member of the S9B family in clan SC of the serine proteases. The protein has been shown to have post-proline dipeptidyl aminopeptidase activity, cleaving Xaa-Pro dipeptides from the N-termini of proteins. Although the activity of this protein is similar to that of dipeptidyl peptidase 4 (DPP4), it does not appear to be membrane bound. In general, dipeptidyl peptidases appear to be involved in the regulation of the activity of their substrates and have been linked to a variety of diseases including type 2 diabetes, obesity and cancer. Several transcript variants of this gene have been described but not fully characterized. More specifically, DPP9 interacts with the NLRP1 protein and affects the level of activation of the NLRP1 inflammasome. This function involves binding to a complex of full-length NLRP1 and a proinflammatory fragment of NLRP1 after activation by autocleavage. A similar mechanism allows DPP9 to regulate the CARD8 inflammasome. This gene has also been linked to severe COVID-19.
Dipeptidyl peptidase that cleaves off N-terminal dipeptides from proteins having a Pro or Ala residue at position 2 (PubMed:12662155, PubMed:16475979, PubMed:19667070, PubMed:29382749, PubMed:30291141, PubMed:33731929, PubMed:36112693). Acts as a key inhibitor of caspase-1-dependent monocyte and macrophage pyroptosis in resting cells by preventing activation of NLRP1 and CARD8 (PubMed:27820798, PubMed:29967349, PubMed:30291141, PubMed:31525884, PubMed:32796818, PubMed:36357533, PubMed:36112693). Sequesters the cleaved C-terminal part of NLRP1 and CARD8, which respectively constitute the active part of the NLRP1 and CARD8 inflammasomes, in a ternary complex, thereby preventing their oligomerization and activation (PubMed:34019797, PubMed:33731929, PubMed:33731932). The dipeptidyl peptidase activity is required to suppress NLRP1 and CARD8; however, neither NLRP1 nor CARD8 are bona fide substrates of DPP9, suggesting the existence of substrate(s) required for NLRP1 and CARD8 inhibition (PubMed:33731929). {ECO:0000269|PubMed:12662155, ECO:0000269|PubMed:16475979, ECO:0000269|PubMed:19667070, ECO:0000269|PubMed:27820798, ECO:0000269|PubMed:29382749, ECO:0000269|PubMed:29967349, ECO:0000269|PubMed:30291141, ECO:0000269|PubMed:31525884, ECO:0000269|PubMed:32796818, ECO:0000269|PubMed:33731929, ECO:0000269|PubMed:33731932, ECO:0000269|PubMed:34019797, ECO:0000269|PubMed:36112693, ECO:0000269|PubMed:36357533}
DPP9 is also known as DP9, DPLP9, DPP IX, DPRP-2, DPRP2, HATIS, IMD111.
